Nigeria struggles with largest recorded Lassa fever outbreak

An emergency meeting on the control of Lassa fever in Abuja, Nigeria. Photo by: REUTERS / Afolabi Sotunde

LAGOS, Nigeria — Nigeria is under pressure to declare a national health emergency as it struggles to contain its largest recorded outbreak of Lassa fever, which has killed 161 people since the start of the year.

What next in the fight against Lassa fever?

Fifty years after it was first identified, outbreaks of the Ebola-like disease in West Africa are only getting worse.

The Nigerian Academy of Science cites a growing number of cases as the dry season peaks and an “unacceptably high” fatality rate as reasons for the government to take immediate action.

Lassa fever, a viral hemorrhagic fever, is endemic in some parts of West Africa. It is usually passed on through food contaminated with infected rat urine or feces.

Nigeria experiences yearly outbreaks that peak during the dry season from November to May, but cases have been rising rapidly over the past few years, with each year's outbreak surpassing the last.

The number of suspected cases in 2020 jumped to 3,735, with 906 cases confirmed as of March 15, according to the Nigeria Centre for Disease Control.

The figures dwarf the total number of laboratory-confirmed cases — 308 in 2017, 633 in 2018, and 810 in 2019, which was previously the year with the highest number of cases, although 2018 saw the highest number of deaths at 171.

An explanation for the surge in numbers remains elusive, but Kalu Onuoha, president of NAS, said in a statement that it could be the result of “an explosive population of rodents generated by pervasive poor environmental sanitation.” Some suggest climate change could also be contributing.

While drugs are available to treat the disease, inefficient diagnosis of patients and delayed hospital admissions mean they are less effective than they otherwise would be, Onuoha added.

But Dr. Ifeanyi Nsofor, a 2019 fellow of George Washington University’s Atlantic Fellows for Health Equity program, said the rise in numbers could also be attributed to improved levels of diagnosis. The fatality rate for the current outbreak is 17.8% — lower than the 23.3% reported for the same period last year — which could be connected to better management of the disease. Still, Nsofor said that prevention efforts are clearly not working, citing a “dysfunctional” primary health care system.

Lassa fever was first reported in Nigeria in 1969, but according to NAS, the overwhelming majority of suspected cases have been reported since 2016.

Nigerian health authorities are intensifying efforts to contain the outbreak, operating five laboratories for testing and dozens of treatment centers. The Nigeria Centre for Disease Control is providing a toll-free phone number and issuing health advisories to promote prevention measures.

The outbreak takes place as Nigeria races to tackle the novel coronavirus that causes COVID-19 after eight cases were confirmed in the country. Dozens of people have been screened in seven states.

Most of the infectious diseases afflicting Nigeria originate from animals — including Lassa fever, monkeypox, yellow fever, and now COVID-19. In December, the country launched a One Health plan to get the Federal Ministry of Health, Federal Ministry of Environment, and Federal Ministry of Agriculture & Rural Development working together to step up prevention, detection, and response.

Update, March 18, 2020: This story was updated with new numbers released by the government after publication.

About the author

  • Linus Unah

    Linus Unah is a Nigerian journalist covering global health, conflict, agriculture, and development. His work has appeared in The Guardian, IRIN, NPR, NewsDeeply, The Christian Science Monitor, among others.